"Just look at what devastation can do to house prices when one's neighbours are in trouble - then try replicating that across the counrty.
It also doesn't take many of those 2 million landlords in Australia to lose their shirt to take the market down the sewer."
That is a different point altogether. Agreed a smaller number of sales will drive the market price up/down. The question is based on that price movement how many that are on the edge will actually be called upon to top up their equity when the repayment schedule is being met(primarily owner occupiers) - the vast majority won't be called upon IMHO as the government will step in long before that happens on a mass scale.
